Caseless ammunition cartridge

ABSTRACT

A caseless ammunition cartridge comprised of a support tube carrying a projectile at one end and a primer cup at the other. A neck portion of the same material as the primer cup is secured at the top of the support tube and a plurality of explosive discs are provided around the support tube between the primer cup and the neck portion.

ilnited States Patent Inventors Appl. No.

Filed Patented Assignee Joseph B. Quinlan Philadelphia County;

Elwood Vetter, Bucks County, Pa.

Feb. 14, 1969 Jan. 26, 197 1 the United States of America as represented by the Secretary of the Army CASELESS AMMUNITION CARTRIDGE 9 Claims, 1 Drawing Fig.

[1.8. CI 102/38, 102/ lOl Int. Cl F42b 5/18 [50] Field of Search 102/38, C.C.Digest, 43, 100, 101

[56] References Cited UNITED STATES PATENTS 3,345,945 lO/l967 Quinlan et al. 102/38 3,482,516 12/1969 Farmer et al. 102/38 Primary Examiner-Robert F. Stahl Att0rneys-Harry M. Saragovitz, Edward .1. Kelly, Herbert Berl and S. Dubroff ABSTRACT: A caseless ammunition cartridge comprised of a support tube carrying a projectile at one end and a primer cup at the other. A neck portion of the same material as the primer cup is secured at the top of the support tube and a plurality of explosive discs are provided around the support tube between the primer cup and the neck portion.

PATENIEUM26 8?! 1 $557,700

INVENTORJ,

JOSEPH B.QUINLAN ELWQOD VETTER y .1 MW 3 14 WornayS.

11 CASELESS AMMUNITION CARTRIDGE The invention describedherein may be manufactured, used, and licensed by or for the Governmentfor governmental purposes without the payment to use of any royalty thereon.

The invention relates to caseless ammunition, and more particularly to caseless ammunition of the cartridge type for small arms such as military rifles and the like.

Without the advent of caseless ammunition, the problems of both velocity'adjustment or Correction and'complete burn out became acute. Because the amount of riiolded' propellant necessary to achieve a specific velocity is standard, the mold which is shaped to form the propellant can only be utilized in the preparation of one size round or cartridge. For each change in velocity requirement, a new or differentsize mold has to be provided. The presentinvention-solves this problem by providing an improved caseless cartridge construction with propellant means that can be varied to provide the desired velocity, while utilizing only one size'moldLThis'rheans also provides more complete burn out in a manner to be described.

It is therefore an object; of the present invention to provide improved caseless cartridge type ammunition which has means that can. be changed to establish different velocities without change in mold size.

Another object of this invention is the provision of improved caseless cartridge-type ammunition which may be constructed of self-supporting combustible elements and which completely burns out during firing. v I

Another object of this invention is the provision of improved caseless cartridge-type ammunition which is adapted to use a plurality of combustible elements in concentric relation in each unit thereof for velocity adjustmentand complete burn out on firing. v

It is a further object of this invention to provide a caseless small arms cartridge that is readily adjustable to velocity requirements and which is of simplified and rugged construction adapted for easy manufacture.

The above objects as well as others together with the benefits and advantages of the invention will be apparent upon reference to the detailed description set forth below, particularly whenconsidered with reference to the accompanying drawing to which attention is directed and in which a cartridge or round of caseless ammunition embodying the inv'ention, is indicated generally .by the reference numeral 10. The cartridge 10 includes a central rigid cylindrical support tube 12 of laminated construction comprising a plurality of. layers of sheet propellant of thedouble-base type preferably spirally wrapped The sheet propellant generally used for this tube is in three or four layers and is a compound mixture of nitroglycerine and nitrocellulose in thin sheet form and known as military M-8.

A projectile, such as a bullet 18', is secured in the forward end M of the support tube which isof an inside diameter to provide a tight press fit therewith. A primer cup 20 as a cartridge base, and for ignition, is secured to the rearward end 16 of the tube. The primer cup or base is moldedsolid from a single-base propellant, such as nitrocellulose and a binder known as military lMR-4809, of relatively fine grain 'for fast burning, and contains a central primer pocket 22 in its rear or base end in which a standard primer composition 24, such as a lead stephanate composition, is located. The primercup as a cartridge base is effectively a round and relatively thick disc pro vided on its upper side with an integral central stud or boss 25 which fits the rear end. of the support tube and with a surrounding annular shoulder 26 against which the rearward end 16 of the support tube 12 is firmly seated.

A plurality of explosive propellant discs 28, cut from sheet propellant of the double-base type such as the M-8 above, are stacked on and fit around said support tube 12 and fill the space along the support tube 12 between the primer cup or base 20 and a forward molded annular neck ring 30. The latter is a composition of a single base propellant, such as nitrocellulose and a binder, and is shaped to fit snugly around the forward end 14 of the support tube 12 as indicated. This is of the same outside diameter as the primer cup or base 20 and determines therewith .the outside diameter of the cartridge. While the neck ring30 ismoldedof the same nitrocellulosesinglcbase propellant materialas the primer cup or base 20, it is of a coarser grain so that it is slowerburning. This may be a propellant known as military type [MR-4895, for example. which provides the desired grain size.

In order to adjust the velocity capability of the cartridge 10, the number of discs or rings 28 which are used is varied. This isdone according to the amount of propellant necessary to achieve aspecific projectile or bullet velocity. More discs are used to, increase velocity andless discs are usedto decrease velocity. Thus with a given propellant composition for the stack of disc charges, such assingle base or double base, the ballistic performance of the cartridge can be changed by changing the web or thickness and the number of propellant discs. The complete burn out necessary for the proper functioning of the round is achieved because the plurality of discs,

rather than one moldedpropellant body, provides-many more 7 surfaces exposed to the hot combustion gases and hence a faster and complete burn out thereof.

From the foregoing description it will be seen that the cartridge is readily adaptedfor adjustment to different velocity requirements without change in overall mold size and is adapted for complete burn out. lt is furthermore adapted for easy manufacture and assembly. The central support tube 12 providesa support for the projectile 18 and the stack of disc charges 28. It further adds internal strength to the cartridge as a tubular core element, and provides a central combustion space or chamber behind the projectile extending to the base or ignition means 20.

The projectile or bullet 18, which tightly seats in the forward end of the support tube, may be of any required weight and diameter or caliber. By way of example, for 5.56 mm or .223 Remington c'alibe'r, the bullet may be .224 inch in diameter and have a weight of 55 grams. Forthis caliber the overall length of the complete cartridge is approximately 1.5 inches and the body of the cartridge is of a diameter to fit the intended firing chamber, and for this caliber is made to .370 inch.

The molded primer cup 20, seated in the opposite or rear end of the support tube from thebullet, not only provides means for ignition of the propellant stack and support tube in response to detonation of the primer material 24, but also provides a solid base for the cartridge and a seat for both the propellant stack and the support tube.

The body of the cartridge, provided mainly by the stacked propellant discs or disc charges 28, is of the same diameter throughout from the base or primer cup 20 to the neck ring 30 and is molded together with the support tube as a unit. The propellant stack thus provides the main energy for firing the projectile and may be varied while using the same propellant material by changing the number and/or thickness of the discs to change the ballistic performance of the ammunition produced in this way.

The caseless cartridge of the all the advantages common to caseless ammunition types in the saving of brass or other shell metal, which is generally critically short in supply in times of national crises and need, along with a saving of carrying weight for troops and toxic fumes from ejected shells in closed combat vehicles.

We claim: l. A caseless ammunition cartridge comprising in combination:

a central cylindrical support tube of propellant material having a forward and a rearward end; a projectile seated in and projecting from said forward end; ignition means of molded propellant material attached to said rearward end in coaxial relation to said tube as a base for said cartridge; a plurality of circular propellant discs stacked on said base and along and around said support tube in concentric relation thereto; and

present invention also provides a neck ring of molded propellant material concentric with and around the forward end of said tube and seated on and against said stacked discs as a retaining means therefor.

2. A caseless ammunition cartridge as defined in claim 1, wherein said ignition means includes a round primer cup fitting into the support tube to join therewith and having 'a flat base end containing a primer element.

3. A caseless ammunition cartridge as defined in claim 2, wherein said primer cup includes a shoulder arranged and constructed to provide a seat for the support tube and said stacked propellant discs.

4. A caseless ammunition cartridge as defined in claim 2, wherein the neck ring and the primer cup are of a single-base propellant and wherein the support tube and the propellant discs are constructed of a double-base propellant in sheet fonn.

5. A caseless ammunition cartridge comprising in combination:

a central cylindrical support tube of sheet propellant material of the double-base type providing internal strengthening means for said cartridge and having a forward and a rearward end;

a projectile seated in and projecting from the forward end of the tube;

a round primer cup of molded single-base propellant material seated in and attached to said rearward end in coaxial relation to said tube as a base for said cartridge;

a predetermined number of circular discs of sheet propellant material of the double-base type stacked on said base and along said support tube in concentric relation thereto to determine the projectile velocity upon firing; and

an annular neck ring of molded single-base propellant material concentric with and around the forward end of said tube and seated on and against said stacked discs as a retaining means therefor.

6. A caseless ammunition cartridge as defined'in claim 5, wherein the material of the propellant discs and of the support tube is a compound of nitrocellulose and nitroglycerine, and wherein the material of the primer cup and of the neck ring is a mixture of nitrocellulose and a binder.

7. A caseless ammunition cartridge comprising in combination:

a central cylindrical support tube of double-base sheet propellant material in wrapped layers;

said support tube having a forward and a rearward end and providing an open tubular strengthening means for said cartridge along the axis thereof;

a projectile seated in and projecting from said forward end with a tight press tit therein;

ignition means of molded single-base propellant material including a round disclike primer cup of the diameter of the cartridge and larger in diameter than said support tube attached to said rearward end in coaxial relation to said tube as a base for said cartridge;

a plurality of circular propellant discs of uniform thickness and of the same outside diameter as the primer cup stacked on said base againstsaid shoulder and along and around said support tube in concentric relation thereto;

said discs being of the same double-base sheet propellant material as the support tube and providing the main firing energy for said cartridge;

a neck ring of molded single-base propellant material concentric with and around the forward end of said tube and seated on and against said stacked discs as a retaining means therefor; and

said ring being of the same outside diameter as the primer cup and the stacked discs and providing therewith a unitary cylindrical cartridge body of unifonn diameter for fitting a firing chamber.

8. A caseless ammunition cartridge comprising in combination:

a central cylindrical support tube of laminated construction comprising .a plurality of layers of propellant material providing internal strengthening means for said cartridge and having a forwardand a rearward end;

a projectile seated in and projecting from the forward end of the tube;

a round primer cup of molded propellant material seated in and attached to said rearward end in coaxial relation to said tube as a base for said cartridge and having an annular shoulder against which said tube is seated;

a predetermined number of circular propellant disc charges stacked on said base against said shoulder and along and around said support tube in concentric relation thereto to determine the projectile velocity upon firing;

said support tube and disc charges being of like sheet propellant material of the double-base type;

an annular neck ring of molded propellant material concentric with and around the forward end of said tube and seated on and against said stacked disc charges as a retaining means therefor; and

said molded primer cup and neck ring being of the same single-base propellant material with different grain size.

9. A caseless ammunition cartridge as defined in claim 6, wherein the support tube and primer cup base with the stack of disc charges and neck ring are joined in concentric relation to provide a body for said cartridge of unitary construction and uniform outside diameter to fit a firing chamber, and wherein the laminated support tube is open between the projectile and the primer base to provide a combustion space in rear of said projectile. 

1. A caseless ammunition cartridge comprising in combination: a central cylindrical support tube of propellant material having a forward and a rearward end; a projectile seated in and projecting from said forward end; ignition means of molded propellant material attached to said rearward end in coaxial relation to said tube as a base for said cartridge; a plurality of circular propellant discs stacked on said base and along and around said support tube in concentric relation thereto; and a neck ring of molded propellant material concentric with and around the forward end of said tube and seated on and against said stacked discs as a retaining means therefor.
 2. A caseless ammunition cartridge as defined in claim 1, wherein said ignition means includes a round primer cup fitting into the support tube to join therewith and having a flat base end containing a primer element.
 3. A caseless ammunition cartridge as defined in claim 2, wherein said primer cup includes a shoulder arranged and constructed to provide a seat for the support tube and said stacked propellant discs.
 4. A caseless ammunition cartridge as defined in claim 2, wherein the neck ring and the primer cup are of a single-base propellant, and wherein the support tube and the propellant discs are constructed of a double-base propellant in sheet form.
 5. A caseless ammunition cartridge comprising in combination: a central cylindrical support tube of sheet propellant material of the double-base type providing internal strengthening means for said cartridge and having a forward and a rearward end; a projectile seated in and projecting from the forward end of the tube; a round primer cup of molded single-base propellant material seated in and attached to said rearward end in coaxial relation to said tube as a base for said cartridge; a predetermined number of circular discs of sheet propellant material of the double-base type stacked on said base and along said support tube in concentric relation thereto to determine the projectile velocity upon firing; and an annular neck ring of molded single-base propellant material concentric with and around the forward end of said tube and seated on and against said stacked discs as a retaining means therefor.
 6. A caseless ammunition cartridge as defined in claim 5, wherein the material of the propellant discs and of the support tube is a compound of nitrocellulose and nitroglycerine, and wherein the material of the primer cup and of the neck ring is a mixture of nitrocellulose and a binder.
 7. A caseless ammunition cartridge comprising in combination: a central cylindrical support tube of double-base sheet propellant material in wrapped layers; said support tube having a forward and a rearward end and providing an open tubular strengthening means for said cartridge along the axis thereof; a projectile seated in and projecting from said forward end with a tight press fit therein; ignition means of molded single-base propellant material including a round disclike primer cup of the diameter of the cartridge and larger in diameter than said support tube attached to said rearward end in coaxial relation to said tube as a base for said cartridge; a plurality of circular propellant discs of uniform thickness and of the same outside diameter as the primer cup stacked on said base against said shoulder and along and around said support tube in concentric relation thereto; said discs being of the same double-base sheet propellant material as the support tube and providing the main firing energy for said cartridge; a neck ring of molded single-base propellant material concentric with and around the forward end of said tube and seated on and against said stacked discs as a retaining means therefor; and said ring being of the same outside diameter as the primer cup and the stacked discs and providing therewith a unitary cylindrical cartridge body of uniform diameter for fitting a firing chamber.
 8. A caseless ammunition cartridge comprising in combination: a central cylindrical support tube of laminated construction comprising a plurality of layers of propellant material providing internal strengthening means for said cartridge and having a forward and a rearward end; a projectile seated in and projecting from the forward end of the tube; a round primer cup of molded propellant material seated in and attached to said rearward end in coaxial relation to said tube as a base for said cartridge and having an annular shoulder against which said tube is seated; a predetermined number of circular propellant disc charges stacked on said base against said shoulder and along and around said support tube in concentric relation thereto to determine the projectile velocity upon firing; said support tube and disc charges being of like sheet propellant material of the double-base type; an annular neck ring of molded propellant material concentric with and around the forward end of said tube and seated on and against said stacked disc charges as a retaining means therefor; and said molded primer cup and neck ring being of the same single-base propellant material with different grain size.
 9. A caseless ammunition cartridge as defined in claim 6, wherein the support tube and primer cup base with the stack of disc charges and neck ring are joined in concentric relation to provide a body for said cartridge of unitary construction and uniform outside diameter to fit a firing chamber, and wherein the laminated support tube is open between the projectile and the primer base to provide a combustion space in rear of said projectile. 